Pituitary tumor resection in a patient with SARS-CoV-2 (COVID-19) infection. A case report and suggested airway management guidelines / Assistência perioperatória de paciente com infecção pelo SARS-CoV-2 (COVID-19) submetido a ressecção de tumor de hipófise urgente. Relato de caso e diretrizes para manejo de via aérea

Abstract The 2020 pandemic caused by the novel coronavirus, COVID-19, had its headquarters in China. It causes Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and presents a broad spectrum of clinical manifestations, ranging from entirely asymptomatic through severe acute respiratory failure and death. Presuming a significant quantity of ventilator-dependent patients, several institutions strategically delayed elective surgeries. Particularly procedures performed involving the nasal mucosa, such as a transsphenoidal approach of the pituitary gland, considering the tremendous level of viral shedding. Nevertheless, critical cases demand expeditious resolution. Those situations are severe pituitary apoplexy, declining consciousness level, or risk of acute visual loss. This case presents a successful urgent perioperative management of a 47 year-old male COVID-19 positive patient who presented to the Emergency Department with a left frontal headache that culminated with diplopia, left eye ptosis, and left visual acuity loss after 5 days. Transsphenoidal hypophysectomy was uneventfully performed, and the patient was discharged from the hospital on postoperative day four. It additionally describes in detail the University of Mississippi Medical Center airway management algorithm for patients infected with the novel coronavirus who need emergent surgical attention.

Resumo A pandemia de 2020 causada pelo novo coronavírus, COVID-19, teve seu epicentro na China. Causa Síndrome Respiratória Aguda Grave pelo Coronavírus 2 (SARS-CoV-2) e apresenta um amplo espectro de manifestações clínicas, que vão desde nenhum sintoma a insuficiência respiratória aguda grave e óbito. Com a expectativa de um número significativo de pacientes dependentes de ventilador, várias instituições estrategicamente adiaram cirurgias eletivas. Esse é o caso principalmente de procedimentos envolvendo a mucosa nasal, como a via transesfenoidal para a hipófise, devido ao nível imenso de disseminação de material viral. Não obstante, casos críticos requerem resolução acelerada. Essas situações são grave apoplexia hipofisária, diminuição do nível de consciência ou risco de perda visual aguda. O presente caso relata o manejo perioperatório bem sucedido de urgência de paciente do sexo masculino de 47 anos de idade com COVID-19 que chegou ao Pronto Socorro com cefaleia frontal à esquerda que culminou com diplopia, ptose do olho esquerdo e perda de acuidade visual à esquerda após 5 dias. A hipofisectomia transesfenoidal ocorreu sem intercorrências e o paciente recebeu alta do hospital no quarto dia do pós-operatório. Adicionalmente, descrevemos em detalhe o algoritmo de manejo de via aérea da University of Mississippi Medical Center para pacientes infectados pelo novo coronavírus e que necessitam de atenção cirúrgica de emergência.

Tratamiento quirúrgico de los adenomas hipofisarios en el Noroeste Argentino / Surgical treatment of pituitary adenomas in the Argentine Northwest

Introducción: Los tumores de hipófisis representan aproximadamente un 10% de los tumores intracraneales. Los adenomas hipofisarios son ampliamente la lesión selar más frecuente. Es fundamental que se conformen equipos capaces de tratar holísticamente esta patología en las distintas regiones de nuestro vasto territorio. El propósito del presente trabajo es presentar nuestra experiencia en el manejo quirúrgico de los adenomas hipofisarios en el Noroeste Argentino. Materiales y métodos: Estudio retrospectivo de pacientes operados por adenomas selares, desde enero de 2013 hasta abril de 2019, en la provincia de Tucumán, por el autor Senior. Resultados: Se analizaron 211 pacientes operados de adenomas pituitarios. En el 75% (n=158) las resecciones fueron totales y en el 25% (n=53) fueron resecciones subtotales. De los 88 pacientes con macroadenomas no funcionantes y déficit visual, el 94% (n=83) presentó mejoría visual en el postoperatorio. De los 52 pacientes con acromegalia, un 75% (n=39) presentó remisión bioquímica completa postquirúrgica. De los 26 pacientes con enfermedad de Cushing, un 81% (n=21) presentó remisión bioquímica completa postquirúrgica. De los 21 pacientes con prolactinomas, un 71% (n=15) normalizaron los niveles de prolactina en el postoperatorio. Conclusión: Los resultados en el tratamiento quirúrgico de los adenomas hipofisarios de la presente serie son comparables a los reportados por centros especializados internacionales. Debemos formar equipos capaces de tratar esta patología en las distintas regiones de la Argentina.

Background: Pituitary tumors account for 10% of intracranial tumors. Pituitary adenomas are the most common selar lesion. It is essential that teams be formed capable of treating this pathology holistically in the different regions of our vast territory. The purpose of this article is to present our experience in the surgical management of pituitary adenomas in the Northwest of Argentine. Materials and methods: A retrospective analysis was done studding patients operated from pituitary adenomas, from January 2013 to April 2019, in Tucumán, by the Senior Author. Results: We analyzed 211 patients operated from pituitary adenomas, of which 75% (n=158) had gross total resections and 25% (n=53) had subtotal resections. Of the 88 patients with non-functioning macroadenomas and visual deficit, 94% (n=83) presented visual improvement after surgery. Of the 52 patients with acromegaly, 75% (n=39) presented complete biochemical remission after surgery. Of the 26 patients with Cushing's disease, 81% (n=21) presented complete biochemical remission after surgery. Of the 21 patients with prolactinomas, 71% (n=15) normalized prolactin levels after surgery. Conclusion: Our results in the surgical treatment of pituitary adenomas are comparable to those reported by international specialized centers. We must form teams capable of treating this pathology in the different regions of Argentina

Recurrent Pituicytoma in a Pediatric Patient: A Case Report

Pituicytoma is a rare tumor that arises from the glial cells of the neurohypophysis. For a long time, it was believed that pituicytomas only appeared in adults. Currently, at least three cases of this entity occurring in children have been reported in the literature. The aim of the present report is to describe the case of a 5-year-old girl who presented to the emergency department with visual disturbances, and the diagnosis was a recurrent pituicytoma. Therefore, the clinical presentation, the radiological features of the tumor, and the corresponding surgical management are described. Additionally, a brief review of the management of this unusual entity was performed.

O pituicitoma é um tumor raro que surge das células gliais da neurohipófise. Durante muito tempo, acreditou-se que os pituicitomas só aparecessem em adultos. Atualmente, pelo menos três casos desta entidade ocorrendo em crianças foram relatados na literatura. O objetivo do presente artigo é descrever o caso de uma menina de 5 anos que chegou à emergência com distúrbios visuais, e o diagnóstico foi um pituicitoma recorrente. A apresentação clínica, as características radiológicas do tumor, e o correspondente manejo cirúrgico foram, portanto, descritos. Além disso, foi realizada uma breve revisão do tratamento desta entidade incomum.

Síndrome de interrupción del tallo pituitario: Relaciones clínicas, bioquímicas y neurorradiológicas / Pituitary stalk interruption syndrome: Clinical, biochemical and neuroradiological relationships

El síndrome de interrupción del tallo pituitario (PSIS) se caracteriza por la demostración neurorradiológica de un tallo pituitario ausente, interrumpido o hipoplásico, adenohipófisis aplásica/hipoplásica o neurohipófisis ectópica. Este síndrome se ha relacionado con formas severas de hipopituitarismo congénito (HPC), asociado a múltiples deficiencias de hormonas pituitarias (MPHD). Evaluamos a pacientes con HPC y PSIS, analizando los signos y los síntomas neonatales al diagnóstico, relacionándolos con las deficiencias hormonales pituitarias y signos neurorradiológicos presentes. Estudiamos retrospectivamente a 80 pacientes asistidos en el Hospital de Niños de Córdoba, con diagnóstico de HPC, de los cuales 42 (52%) presentaron PSIS; 22 mujeres y 20 varones, EC: 5 días-9,5 años. El 62% presentó MPHD y el 38% insuficiencia somatotrófica aislada (IGHD). El análisis de las variables perinatales demostró antecedentes de parto natural en el 52% (11/21) de las MPHD vs. 13% (2/15) de las IGHD. Cuatro pacientes, 2 con MPHD y 2 con IGHD presentaban antecedentes obstétricos consistentes en presentación podálica y transversa respectivamente, todos ellos resueltos mediante operación cesárea. Los signos y los síntomas perinatales fueron hipo- glucemia: 61% en MPHD vs. 19% en IGHD, p: 0,0105; ictericia: 38% en MPHD vs. 25% en IGHD; micropene: 77% en MPHD y colestasis: 19% en MPHD. Convulsiones neonatales se presentaron en el 75% de los niños con MPHD e hipoglucemia. EC media de consulta: 2,1 años en MPHD (30% en el período neonatal, 70% antes de 2 años) y 3,6 años en IGHD (44% en menores de 2 años). Los pacientes con MPHD presentaban: tallo no visible 81% (n: 21/26) vs. tallo hipoplásico: 19% (n: 5/26), p: 0,0001; en IGHD 56% (n: 9/16) vs. 44% (n: 7/16), p: 0,5067, respectivamente. El 100% de los neonatos con HPC tenían tallo pituitario ausente. Concluimos que la demostración de PSIS en niños con HPC proporciona información valiosa como predictor de la severidad fenotípica, la presencia de MPHD y de la respuesta al tratamiento. La baja frecuencia de antecedentes obstétricos posicionales potencialmente distócicos, como parte de los mecanismos fisiopatogénicos responsables de PSIS, indicaría la necesidad de analizar la importancia de posibles factores genéticos y epigenéticos involucrados. El diagnóstico precoz de HPC debe sospecharse en presencia de signos y síntomas clínicos, tales como hipoglucemia, colestasis, micropene y defectos asociados en la línea media facial. La resonancia magnética cerebral debe formar parte de los estudios complementarios en pacientes con esta presunción diagnóstica, especialmente a edades tempranas. El reconocimiento tardío de esta entidad puede aumentar la morbilidad y la mortalidad con efectos potenciales deletéreos y permanentes.

Pituitary stalk interruption syndrome (PSIS) is characterised by the combination of an interrupted or thin pituitary stalk, absent or ectopic posterior pituitary, and anterior pituitary hypoplasia. It is manifested as isolated (IGHD) or combined pituitary hormone deficiencies (CPHD) of variable degrees and timing of onset, with a wide spectrum of clinical phenotypes. PSIS may be an isolated morphological abnormality or be part of a syndrome. A retrospective evaluation is presented of clinical signs and symptoms present at early life stages, as well as an analysis of their relationship with hormone laboratory tests and diagnostic imaging in children with congenital hypopituitarism (CHP), and PSIS. This study was performed in a single centre on a sample of 42 children out of a total of 80 CHP patients, with a chronological age range between 5 days and 9.5 years from a database analysed over a period of 26 years. The study included 26/42 (62%) with CPHD and 16/42 (38%) with IGHD. The analysis of perinatal variables showed a natural delivery in 52% (11/21) of CPHD vs 13% (2/15) of IGHD. Four patients, two with CPHD and two IGHD had breech and transverse presentation respectively. All of them were resolved by caesarean section. The perinatal histories showed hypoglycaemia (61% CPHD vs 19% IGHD, P=.0105), jaundice (38% CPHDvs25% IGHD), micropenis (75%CPHD), hypoglycaemic seizures (75% CPHD), and cholestasis (19% CPHD). The mean CA of consulting for CPHD patients was 2.1 years, 30% in neonatal period and 70% before 2 years. The mean chronical age (CA) was 3.6 years in IGHD patients, with 44% of them less than 2 years. MRI showed that 81% of CPHD patients had absence of pituitary stalk vs 19% with thin pituitary stalk (P=.0001); Patients with IGHD presented 56% absence of pituitary stalk vs 44% with thin pituitary stalk (P=.5067). All (100%) of the patients diagnosed in the neonatal stage had absent pituitary stalk. The characterisation of GH deficient patients by presence and type of hypothalamic-pituitary imaging abnormality provides valuable information as a predictor of phenotypic severity, treatment response, and the potential to develop additional hormonal deficiencies. We conclude that demonstrating PSIS in children with HPC provides valuable information as a predictor of phenotypic severity, presence of MPHD, and response to treatment. The low frequency of potentially dysfunctional positional obstetric history, as part of the pathophysiological mechanisms responsible for PSIS, would indicate the need to analyse the importance of possible genetic and epigenetic factors involved. Early diagnosis of HPC should be suspected in the presence of clinical signs and symptoms, such as hypoglycaemia, cholestasis, micropenis, and associated facial midline defects. MRI should be part of complementary studies in patients with this diagnostic suspicion, especially at an early age. Late recognition of this entity may increase morbidity and mortality with potential permanent deleterious effects.

Serum cortisol concentration in the Colombian creole horse / Concentración del cortisol sérico en el caballo criollo colombiano / Concentração de cortisol sérico no cavalo crioulo colombiano

Abstract Background: Cortisol is indicative of adaptation to physiological factors, disease and environmental stress in equines. Cortisol recently gained attention for its prognostic value in critical disease and as an indicator of fitness and athletic performance. Objective: To determine baseline serum cortisol (SC) morning concentrations in the Colombian creole horse (CCH). Methods: Blood serum was taken from 62 CCH of both genders with and average age of 8.8 years (± 5.3), which were clinically healthy and had different performance levels. Results: The overall SC average determined by sandwich ELISA was 13.3 ± 7.4 mg/dL. No significant differences were attributed to gender, age, or performance. Conclusion: This concentration can be used as a reference value for CCH maintained in low physical activity.

Resumen Antecedentes: El cortisol es un indicador de adaptación a factores de estrés fisiológico, patológico y ambiental en equinos. Recientemente, esta hormona ha ganado interés por su valor en la prognosis de enfermedades críticas y como indicador del nivel de acondicionamiento y rendimiento atlético. Objetivo: Determinar la concentración del cortisol sérico (CS) matinal para el caballo criollo colombiano (CCC). Métodos: Se tomó suero sanguíneo de 62 CCC de ambos sexos, edad promedio 8,8 años (± 5,3), clínicamente saludables, divididos en grupos según edad, sexo y tipo de actividad física. Resultados: La media del CS general determinada por ELISA tipo sándwich fue 13,3 ± 7,4 μg/dL. No hubo diferencias significativas atribuibles a género, edad o desempeño. Conclusión: Esta concentración puede ser utilizada como valor de referencia en CCC que desarrollen actividades de baja exigencia física.

Resumo Antecedentes: O cortisol nos equinos considera-se um hormônio indicador da adaptação a fatores de estresse fisiológico, patológico e ambiental. Recentemente, tem incrementado o interesse por seu valor prognóstico em doenças críticas e como indicador de acondicionamento e rendimento atlético. Objetivo: Determinar a concentração do cortisol sérico (SC) matinal no cavalo crioulo colombiano (CCC). Métodos: Soro sanguíneo foi coletado de 62 CCC, de ambos sexos, idade média de 8,8 anos (± 5,3), clinicamente sadios, divididos em grupos segundo idade, sexo e tipo de atividade física. Resultados: A média geral da SC determinada pela ELISA tipo sanduiche foi 13,3 ± 7,4 μg/dL. Não houve diferenças significativas atribuíveis ao sexo, idade ou desempenho. Conclusão: A concentração determinada pode ser utilizada como valor de referência no CCC que desenvolvem atividades de baixa exigência física.

Apoplejía tumoral pituitaria / Pituitary tumor apoplexy

La apoplejía tumoral pituitaria es un síndrome infrecuente que resulta del infarto y/o hemorragia espontánea de un adenoma pituitario preexistente. Ya que el evento primario involucra el adenoma, este síndrome debe ser nombrado como apoplejía tumoral pituitaria y no como apoplejía pituitaria. El aumento súbito en la presión de los contenidos de la silla turca da como resultado una cefalea de inicio agudo (puede ser incluso una "cefalea en trueno") de intensidad severa, alteraciones visuales y compromiso en la función pituitaria. El diagnóstico se basa en una alta sospecha clínica, imagen por resonancia magnética y medición de hormonas hipofisiarias en sangre. El tratamiento se basa en medidas de soporte (líquidos intravenosos y corticoides) y en casos sin buena respuesta o con deterioro neurológico, descompresión de silla turca. A continuación presentamos el caso de un adenoma previamente no diagnosticado que debutó como apolejía tumoral pituitaria. (Acta Med Colomb 2015; 40: 249-253).

Pituitary tumor apoplexy is an infrequent condition resulting from infarction and/or spontaneous bleeding from a pre-existing pituitary adenoma. This entity requires the prior existence of an adenoma in order to be named as pituitary tumor apoplexy, otherwise, it should be named pituitary apoplexy. The sudden increase in pressure of the sella turcica's contents results in a clinical syndrome characterized by headache (which can be "thunderclap headache"), visual disturbances and hypopituitarism. Diagnosis is not always straight forward and requires high clinical suspicion in addition to magnetic resonance imaging and measurement of serum pituitary hormones. Treatment is mainly based on supportive measures (intravenous fluids and steroids) and surgical decompression in those cases with no response to medical treatment and progressive neurological impairment. We report the case of a patient with a previously unknown pituitary adenoma presenting as a tumor apoplexy. (Acta Med Colomb 2015; 40: 249-253).

Apoplejía postoperatoria de un macroadenoma hipofisiario residual e infarto de la arteria cerebral media / Post-operative apoplexy of a residual pituitary macro-adenoma and middle cerebral artery infarction

La apoplejía postoperatoria de los adenomas hipofisiarios es una complicación rara vez reportada. La presión ejercida por el tumor residular edematoso puede comprometer estructuras nerviosas y vasculares adyacentes a la región selar. Describios el caso de un hombre de 69 años de edad con un tumor selar gigante a quien le fue realizada una resección incompleta a través de un acceso pterional. La cirugía fue detenida por inestabilidad hemodinámica. Cuarenta y ocho horas más tarde, desarrolla oftalmparesias y disminución bilateral de la agudeza visual, deterioro del estado de consciencia, poliuria y hemiparesia izquierda. Una tomografía cerebral simple de emergencia demostró incremento del volumen tumoral con hemorragia y un infarto en el territorio de la arteria cerebral media derecha. El paciente falleció siete días más tarde. Este caso ejemplifica esta rara y catastrófica complicación con alta morbilidad y mortalidad. En la revisión de la literatura, solo fueron encontrados dos casos de ictus isquémico debido a la compresión de arterias intracraneales mayores por apoplejía postoperatoria de macroadenomas residuales.

Postoperative apoplexy of residual pituitary adenomas is a rarely reported complication. Pressure from edematous residual tumor may affect vascular and nervous structures adjacent to sellar region. We described a 69 years old man with a giant sellar tumor who underwent to incomplete resection through pterional approach. Surgery was stopped by hemodynamic instability. Forty-eight hours later, he developed bilateral decreased of visual acuity, bilateral ophthalmoparesis, drowsiness, polyuria and left hemiparesis. An emergency computed tomography scan showed increase in tumor volume with hemorrhage and an infarct of right middle cerebral artery. The patient died seven days later. This case exemplifies this rare and catastrophic complication with high morbidity and mortality. On literature review, only two cases of ischemic strokes due to compression major intracranial arteries by postoperative tumor apoplexy were found.

Pseudoaneurisma carotídeo secundario a cirugía transesfenoidal tratado exitosamente mediante oclusión carotídea con balón de Fogarty / Carotid pseudoaneurysm artery alter transsphenoidal surgery successfully treated with carotid oclusion with Fogarty balloon

Objetivo. Presentar un caso de pseudoaneurisma de carótida después de una cirugía transesfenoidal. Descripción. Paciente portadora de enfermedad de Cushing, previamente operada en tres oportunidades sin resultados favorables. Cuatro semanas después de la cuarta operación en que se logró finalmente resecar el adenoma, fue internada por presentar una hemorragia cataclísmica. Intervención. Se intentó sin éxito un procedimiento endovascular, por lo que como último recurso, se le insertó un balón Fogarty por arteriotomía cervical ocluyendo el seudoaneurisma en la carótida intracavernosa. La paciente se recuperó sin déficit neurológico. Este caso es el primero en la literatura tratado con balón Fogarty para este propósito. Se discuten las principales complicaciones vasculares de la cirugía transesfenoidal como la hipótesis de la eventual cura de la enfermedad de Cushing en este caso.

The authors presented a case of carotid pseudoaneurysm artery after transsphenoidal surgery in a female patient harboring Cushing disease, previously operated 3 times without endocrinological success. After a severe bleeding she was submittedendovascular procedures without results, and dramatically a Fogarty balloon was inserted by arteriotomy in the neck occluding the segment of pseudoaneurysm in intra-cavernous carotid artery, The patient recovered without neurological deficit. Thisrepresents the first case in literature treated with Fogarty balloon for this purpose. The characteristics of the main vascular complications are discussed as well as the hypothesis for the eventual cure of the Cushing disease in this case with a long term follow up. The association between micro-adenomas mainly Cushing are related to be associated with pseudo-aneurysmof carotid artery after transsphenoidal surgery.

McCune-albright syndrome and acromegaly: hormonal control with use of cabergoline and long-acting somatostatin - case report / Síndrome de McCune-albright associada à acromegalia: controle hormonal com cabergolina e somatostatina de longa duração - relato de caso

OBJECTIVES: The use of drug therapy based on cabergoline, octreotide and long-acting release (LAR) octreotide has presented varying results in the treatment of GH excessive production in patients with McCune-Albright Syndrome. METHODS: We report the case of a 29 year-old female patient presenting McCune-Albright Syndrome and complaint of excessive bone growth. RESULTS: The patient presented a pituitary adenoma involving the right internal carotid artery and excessive secretion of growth hormone (no GH suppression was observed after the oral glucose tolerance test). Due to the presence of diffuse thickness in skull base bones, surgical approach was not considered effective and the patient was submitted to drug therapy with octreotide LAR and cabergoline. At the one year follow-up, GH and IGF-1 levels were normal and no adverse effects were present. CONCLUSION: The use of drug therapy based on the association of cabergoline and octreotide is safe and able to achieve complete hormonal control in the treatment of acromegaly for McCune-Albright patients.

OBJETIVO: O uso de terapia medicamentosa, como cabergolina, octreotide e octreotide de longa duração, tem apresentado resultados variados no tratamento da produção excessiva de hormônio de crescimento (GH) em pacientes com síndrome de McCune-Albright. MÉTODOS: Foi relatado o caso de uma paciente de 29 anos apresentando síndrome de McCune-Albright com queixas de crescimento ósseo excessivo. RESULTADOS: A paciente apresentava adenoma pituitário com envolvimento da artéria carótida interna direita e produção excessiva de GH (sem supressão de GH após o teste de supressão com glicose). Por causa do aumento importante da espessura dos ossos da base do crânio, a abordagem cirúrgica foi considerada pouco efetiva e a paciente foi submetida à terapia medicamentosa com octreotide de longa duração e cabergolina. No seguimento de um ano, os níveis de GH e IGF-1 estavam normais e os efeitos adversos não eram presentes. CONCLUSÃO: A terapia medicamentosa fundamentada na associação de cabergolina e octreotide é segura e capaz de alcançar controle hormonal completo no tratamento de acromegalia na síndrome de McCune-Albright.

Neuroimunomodulação: sobre o diálogo entre os sistemas nervoso e imune / Neuroimmunomodulation: the cross-talk between nervous and immune systems

OBJETIVO: Trabalhos de pesquisa provenientes do campo da neuroimunomodulação vêm tornando explícitas as intrincadas relações existentes entre o sistema nervoso central e o sistema imune. Uma revisão bibliográfica foi realizada com o objetivo de descrever as bases de estudo da neuroimunomodulação. MODELOS EXPERIMENTAIS: Sabe-se, hoje, que estados emocionais como ansiedade e depressão são capazes de modificar a atividade do sistema imune como também o fazem o estresse e fármacos com ação no sistema nervoso central. COMPORTAMENTO DOENTIO: Os comportamentos apresentados por um organismo doente devem ser encarados como decorrência de estratégias homeostáticas de cada indivíduo. POSSÍVEIS MECANISMOS DE SINALIZAÇÃO DO SISTEMA IMUNE PARA O SISTEMA NERVOSO CENTRAL: Grande destaque tem sido atribuído para a participação do eixo hipotálamo-pituitária-adrenal, do sistema nervoso autônomo simpático e das citocinas nas sinalizações entre o sistema nervoso central e o sistema imune. CONCLUSÃO: O presente artigo pretende mostrar a relevância dos fenômenos de neuroimunomodulação; ele faz uma análise crítica das influências do sistema nervoso central sobre o sistema imune e vice-versa.

OBJECTIVE: Several papers arriving from the neuroimmunomodulation field are showing the relevant relationships between the nervous and the immune systems. A review of studies was carried out to describe the bases of the studies on neuroimmunomodulation. EXPERIMENTAL MODELS: It is clear nowadays that emotional states such as anxiety and depression change immune system activity, an affect also observed after both stress and use of nervous system acting drugs. SICK BEHAVIOR: The behavior displayed by sick organisms might be thought as being a consequence of homeostatic strategies. POSSIBLE MECHANISM OF THE ACTION BY MEANS OF IMMUNE SYSTEM TO NERVOUS SYSTEM: A very big emphasis is being given to Hipothalamus-pituitary-adrenal axis, simpathetic nervous system and cytokines participation on nervous system and immune system relationships. CONCLUSION: The present revision intend to show some essential studies in the neuroimmunomodulation field; it makes a critical analysis of the mutual relationships between nervous system and immune system.